如何從Firebase實時數據庫中選擇數據

Question

我有一個具有結構的數據庫，大致像

// An index to track Ada's memberships
{
  "users": {
    "alovelace": {
      "name": "Ada Lovelace",
      // Index Ada's groups in her profile
      "groups": {
         // the value here doesn't matter, just that the key exists
         "techpioneers": true,
         "womentechmakers": true
      }
    },
    ...
  },
  "groups": {
    "techpioneers": {
      "name": "Historical Tech Pioneers",
      "members": {
        "alovelace": true,
        "ghopper": true,
        "eclarke": true
      }
    },
    ...
  }
}

但我不知道如何選擇屬於同一組用戶的用戶

Answer 1

您必須定義一個附加的group_combinations或all_groups索引，在其中將每個用戶存儲在他們的組合下：

all_groups: {
  "techpioneers_womentechmakers": {
    alovelace: true
  }
}